I just swapped out the two Grundfos 15-58 pumps on my boiler today with some ECM pumps. The one feeding the house is a new Armstrong 20-20CI which has the same flow curve as the 15-58. The other is a Grundfos Alpha 15-55 which has a slightly lower flow curve. The Alpha is just running a bypass loop since I decided not to heat the building this year that it is connected to.
Both pumps running on high constant speed.
So far I like the Armstrong better.
According to the displays on the the Armstrong, it is using 45 watts and flowing 7 gpm. I connected it to a Kill-a-watt meter and it was a little under 43 watts. (15-58 pump was using 82 watts)
The Alpha display shows 43 watts and was changing from 8-10 GPM. Kill-a-watt showed 43.8w. (15-58 pump on this loop was using 85 watts) I thought this one would have been a lot higher since it is only going through less than 2 feet of pipe and a few corners. I have heard that the GPM reading isn't real accurate on them so maybe it is higher.
I may swap the two at some point just for a better comparison.
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Topic: ECM Pumps (Read 1807 times)